• 한국정밀공학회지
• /
• 제24권1호
• /
• pp.37-46
• /
• 2007

The vibration environment essentially companied by vehicle operation on the ground is determined by the shape of road surface, which is called profile. This paper focuses on development of a profile and severity measurement system for unpaved test courses. In general, the profile and severity of unpaved road is an important issue in the reliability of endurance test. In order to measure unpaved road profile and severity, it is necessary to develop a profilometer system. The developed profilometer system is composed of data processing computer, power unit, air compressor and sensors(encoder, vertical gyro and laser displacement) This paper presents the measuring system configuration, measurement principle of road profile and analysis method of road characteristics used at CPG(Changwon Proving Ground) for this purpose.

• 한국정밀공학회지
• /
• 제24권2호
• /
• pp.47-57
• /
• 2007

The vibration environment essentially companied by vehicle operation on the road is determined by the shape of road surface, which is called profile. In general, the profile and severity of unpaved road is an important issue in the reliability of durability test for vehicles. In order to maintain severity of unpaved road, it is necessary to develop profilometer system. We developed profilometer system which is composed of data processing computer, power unit, air compressor and sensors. This paper focuses on the severity management of unpaved test courses using neural networks. This paper presents the maintenance range for cross-country course in CPG(Chang-won Proving Ground) and the evaluation of similarity degree between unpaved roads.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2007년도 춘계학술대회 논문집
• /
• pp.395-403
• /
• 2007

Railroad track consists of relatively simple structures such as rail, sleeper, ballast. Roadbed shares vertical pressure by train load which passed through rail to ballast as base that supports the track. For evaluating stress and displacement of roadbed due to the railroad load is an important role on the track as a basic data for estimation of the durability and design of the roadbed thickness. GEOTRACK program applied multi-layered theory was developed for analyzing railroad track structure. GEOTRACK program is a sort of numerical analysis program which has advantage that can analysis component of track by simple method. In this study, this program was used to preform the numerical analysis by changing track conditions and roadbed conditions such as tie, reinforced roadbed, dynamic wheel load, Resilient modulus and so on. Further detail will be presented on the paper.

• 한국음향학회:학술대회논문집
• /
• 한국음향학회 2001년도 추계학술발표대회 논문집 제20권 2호
• /
• pp.129-132
• /
• 2001

본 논문에서는 EVRC 음성 부호화 시스템을 7MS320C54x를 이용하여 전 과정을 어셈블리어로 실시간 구현하였다. 구현된 EVRC 음성 부호화기는 최대의 계산량을 요구하는 8kbps 일때 잡음제거 알고리즘을 제치한 인코더부분이 평균 26.3MIPS 이며 디코더부분은 3.6MIPS의 복잡도를 나타낸다. 사용된 메모리양은 프로그램 ROM 16.9K words, 데이터 ROM(table) 7.9K words 및 RAM 5.8K words 이다. 구현된 EVRC 음성 부호화기는 북미 표준화 기구인 TIA(Telecommunications Industry Association)에서 제공하는 19 개의 테스트 백터들을 모두 통과하였다.

• 한국구조물진단유지관리공학회 논문집
• /
• 제1권2호
• /
• pp.115-122
• /
• 1997

Although most bridge foundations are usually constructed by Caisson, terrain difficulties sometimes bring about constructing bridge foundations by Jacket piles. This study investigated the dynamic characteristics of Caisson and Jacket by testing the impact applied to actual bridge foundations. The test result showed that the damping ratio of the foundation constructed by Jacket and Caisson were measured 1-2% and 3-6%, respectively. Considering the lateral deflection measured by the impact test, the rigidity of foundations constructed by Jacket was assessed about 1/5 - 1/6 of those constructed by Caisson. It implies that designing bridge foundations should include and reflect the dynamic analysis of bridge foundation.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2008년도 춘계학술대회 논문집
• /
• pp.1747-1755
• /
• 2008

Design of the reinforced roadbed thickness is concerned with safe operation of trains at specified levels of speed, axle load and tonnage. There are two methods for evaluating it. One is using an experimental equation and the other is using elastic theory with considering axle load, material properties of subsoils and allowable elastic settlement. Multi-layered theory is used to determine reinforced roadbed thickness by RTRI. Although their reinforced roadbed thickness is designed with an objective of achieving a minimum standard 2.5mm of settlement on the subgrade surface, it is hardly applied to real design. Li(1994) has suggested the experimental model which design approach is to limit plastic strain and deformations for the design period. It is worth due to adopting soil equivalent number of repeated load application. Moreover, it has been a more advanced method than existing design methods because including resilient modulus of subsoil beneath track, soil deviator stress caused by train axle loads and MGT. In this paper, it is analyzed under domestic track conditions to estimate the reinforced roadbed thickness with different soil types.

• Journal of Mechanical Science and Technology
• /
• 제15권6호
• /
• pp.693-698
• /
• 2001

The analysis of actuating forces (or torques) and joint reaction forces (or moments) are essential to determine the capacity of actuators, to control the system and to design the components. This paper presents an inverse dynamic analysis algorithm for flexible multibody systems with closed-loops in the relative joint coordinate space. The joint reaction forces are analyzed in Cartesian coordinate space using the inverse velocity transformation technique. The joint coordinates and the deformation modal coordinates are used as the generalized coordinates of a flexible multibody system. The algorithm is verified through the analysis of a slider-crank mechanism.

• 대한기계학회논문집A
• /
• 제20권12호
• /
• pp.3741-3747
• /
• 1996

This paper presents a method for the inverse dynamic anlaysis of mechanical systems. Actuating forces(or torques) depending on the driving constraints are analyzed in the relative coordinate space using the velocity transformation technique. A systematic method to compose the inverse velocity transformation matrix, which is used to determine the joint reaction forces, is proposed. Two examples are taken to verify the method developed here.

• 한국약용작물학회:학술대회논문집
• /
• 한국약용작물학회 2012년도 심포지엄 및 춘계학술발표회
• /
• pp.321-322
• /
• 2012

• 대한예방한의학회지
• /
• 제15권1호
• /
• pp.17-27
• /
• 2011

Objective : The purpose of this study was to identify the trend of research in the Korean Journal of Oriental Preventive Medicine and to suggest future perspective for oriental preventive medicine research. Method : The contents of 344 articles published in this journal was reviewed from its beginning year 1997 to year 2010. Result : The number of articles was increased as times go on. An analysis of the research design showed, experimental research (in vivo or in vitro) was 36.9%, survey research was 26.5%, review was 20.1%. In the major classifications of topics published, health management 28.5%, oriental medicine effectiveness 25.3%, herbal safety and toxicity 13.1%, and environmental and occupational medicine 9.0% respectively. Conclusion : There has been a lack of health preservation(Yang-saeng) topic, epidemiology and health statistics topic. Further research need qualitative study and each subjects of oriental preventive medicine.